Hundreds of climate protesters will form a human chain at Kingsnorth power station in what will be the biggest test of Kent police tactics since its controversial handling of last year's demonstrations.

Protesters from a coalition of groups, including Oxfam, the Women's Institute, Greenpeace, and the RSPB, will form the chain around the parts of the plant that are not subject to court injunctions.

The chain, dubbed a "Mili-band of polite radicals", is intended to intensify the pressure on the climate change secretary, Ed Miliband, to throw out plans by E.ON for a new coal-fired plant on the site.

The Kent force has admitted its policing, including the filming of journalists, was at fault during last August's Kingsnorth climate camp. The blanket search of protesters is the subject of a judicial review. The force was also criticised in a report for playing loud music, including Wagner and the theme from 80s sitcom Hi-de-Hi, to wake protesters.

"We have people from Bristol to Birmingham coming down to Kent to show, injunction or not, their opposition to this wretched scheme," said Thomas Schultz-Jagow, Oxfam's campaigns director.

"A broad coalition of twitchers and knitters will be there, with their picnics, to show that you don't have to be an anarchist to protest. We hope this demonstration of well-mannered radicals shows Ed Miliband and E.ON that this scheme is one of such recklessness that it has to stop."

The proposed new £1.5bn plant will utilise post-combustion technology, which removes 20-25% of emissions from the power station. The plant will pump out 6m tonnes of carbon into the atmosphere every year.

With UN climate change talks taking place in Copenhagen later this year, protest groups want the UK government to set an example by refusing new coal power stations. Any that are granted should use pre-combustion carbon capture, which removes 80% of emissions, they insist.

An E.ON spokeswoman said the plant would test post-combustion technology and lead to future efficiency gains. She said protest organisers had been clear about their aims but the firm had concerns about anyone being "silly".

"We have a history of people trying to get into the power station. We are making sure it is safe," she said.

Kent police tactics were criticised last year. Two women who challenged officers for not displaying their badge numbers were bundled to the ground, arrested and held in prison for four days, according to an official complaint lodged last month.

A Kent police spokeswoman said the force had worked with E.ON and protesters to ensure that anyone wanting to attend could do so.